Smarter in 60 Seconds: Illusions
The human ear fails to capture quite a bit: For instance, it can only perceive two tones if they are sufficiently different from each other. Furthermore, a loud noise can completely mask a quieter sound after and even before it. In short: When an orchestra is playing, an untrained ear will take in only about 15% of the acoustic data being generated. The MP3 audio format exploits this phenomenon and removes all “inaudible” tones, such as soft sounds. This usually reduces the memory requirements of a song by approximately 90%. In a physical sense the original and the copy are worlds apart, but for the vast majority of people, they sound the same.